Improving the appearance of the skin has been the goal of many esthetic products and procedures for many years, since a tight skin, without wrinkles or cellulite, has a younger and more appealing appearance.
The skin and muscles of the face are structured differently than other places on the body. One side of the facial muscles is connected to the bone and the other to the skin. As the muscle deteriorates through the aging process, the attached facial skin loses it elasticity. Loss of elasticity causes the skin to sag and wrinkle. Strengthening relevant muscle groups restores and maintains the original shape and contour of the muscles. As facial muscles get stronger, they get shorter and flatter, causing the attached skin to become firmer, and smoothing wrinkles, improving facial appearance. Additionally, a contracting muscle's blood supply is 10 times greater than a muscle at rest. This fresh blood supply delivers vital oxygen and nutrients to the skin, revitalizing the tissue.
One way of exercising muscle groups which are not normally used, such as superficial facial muscles, is electrotherapy, which is the use of electrical currents applied to the skin by electrodes. The current flowing between the electrodes excites the muscles and the nerves leading to the muscles between those electrodes.
A specific type of electrotherapy, called micro-current electrical neuromuscular stimulation (MEMS), employs very small currents (in the range of microamperes), which result in almost no discomfort or sensation to the skin. They are becoming more widely accepted for the treatment of pain relief and tissue healing, by affecting the injured tissue at the cellular level [Gardner S E, Frantz R A, Schmidt F L (1999). “Effect of electrical stimulation on chronic wound healing: a meta-analysis”. Wound Repair Regen 7 (6): 495-503].
Several devices have used electrotherapy for the purpose of skin rejuvenation and cosmetic treatment of wrinkles. Years of experience using those devices have shown that excitable tissues will accommodate to stimulation, unless the stimulation is dynamic to prevent accommodation.
Various methods of dynamic excitation have been proposed. The first relates to modulation of the input currents (varying sinusoidal waveform). Common modulation schemes include amplitude modulation (AM) in which the amplitude of the signal is varied, Frequency modulation (FM), in which the frequency of the signal is varied, and phase modulation (PM), in which the phase of the signal is varied.
Most electrotherapy devices base their input currents on pulses, usually square waveform pulses. These can also be modulated. Common modulation schemes for pulses include Pulse-code modulation (PCM), Pulse-width modulation (PWM), Pulse-amplitude modulation (PAM), Pulse-position modulation (PPM) and Pulse-density modulation (PDM). For example, patent application no. US 20005397338 discloses a device for delivering electrical energy to subcutaneous tissues for pain control and promotion of tissue healing using pulse width modulation scheme in which the pulse width is varied in a sinusoidal fashion from 60 microseconds to 170 microseconds.
Another method of modulating alternating pulses includes a predetermined combination of square pulses, not modulated by a mathematical formula. Such a combination is disclosed, for example, in U.S. Pat. No. 7,110,826. Furthermore U.S. Pat. No. 7,110,826 discloses electrical currents (of about 500 μA or less) that are similar to the humane body. Moreover, U.S. Pat. No. 7,110,826 discloses electrical voltage signals at the range of 0.3 V to about 3.9 V. The present invention, on the contrary, applies different electrical currents of about 1 milliampere, and voltages greater than 4V. Surprisingly, such signals were found to have a much greater esthetic effect on the skin. Furthermore, in the present application essentially different electrical currents are applied simultaneously on the skin for obtaining better esthetic results.
These various devices rely on the fact that even small differences in the current level, the method of excitation, the repetition of the excitation and the waveform may transform a therapeutic process to a harmful one. Therefore, the optimal use of electrotherapy depends more on experimentation than on theoretical design. The theory can only offer various solutions, but their efficacy can only be proven clinically.
Thus, there is still a long felt need for a device that uses a modulation scheme fit for improving skin viability and skin rejuvenation, relies on experimental or feedback loop for optimal results, easy to use, safe and complies with international safety standards.